Messages in this thread | | | Date | Fri, 13 Oct 2023 20:59:26 -0400 | From | matoro <> | Subject | Re: Possible bug report: kernel 6.5.0/6.5.1 high load when CIFS share is mounted (cifsd-cfid-laundromat in"D" state) |
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On 2023-10-13 20:13, Steve French wrote: > Let me know if those fixes help as two of them have not been sent to > Linus > yet, but I could send tomorrow > > On Fri, Oct 13, 2023, 19:01 Paulo Alcantara <pc@manguebit.com> wrote: > >> You probably want these two as well >> >> >> https://git.samba.org/?p=sfrench/cifs-2.6.git;a=commit;h=2da338ff752a2789470d733111a5241f30026675 >> >> >> https://git.samba.org/?p=sfrench/cifs-2.6.git;a=commit;h=3b8bb3171571f92eda863e5f78b063604c61f72a >> >> as directory leases isn't supported in SMB1, so no waste of system >> resources by having those kthreads running. >> >> On 13 October 2023 20:52:11 GMT-03:00, Paulo Alcantara >> <pc@manguebit.com> >> wrote: >> >Could you please try two commits[1][2] from for-next? >> > >> >[1] >> https://git.samba.org/?p=sfrench/cifs-2.6.git;a=commit;h=e95f3f74465072c2545d8e65a3c3a96e37129cf8 >> >[2] >> https://git.samba.org/?p=sfrench/cifs-2.6.git;a=commit;h=81ba10959970d15c388bf29866b01b62f387e6a3 >> > >> >On 13 October 2023 20:19:37 GMT-03:00, matoro < >> matoro_mailinglist_kernel@matoro.tk> wrote: >> >>On 2023-10-05 05:55, Dr. Bernd Feige wrote: >> >>> Am Dienstag, dem 26.09.2023 um 17:54 -0700 schrieb Paul Aurich: >> >>>> Perhaps the laundromat thread should be using msleep_interruptible()? >> >>>> >> >>>> Using an interruptible sleep appears to prevent the thread from >> >>>> contributing >> >>>> to the load average, and has the happy side-effect of removing the >> >>>> up-to-1s delay >> >>>> when tearing down the tcon (since a7c01fa93ae, kthread_stop() will >> >>>> return >> >>>> early triggered by kthread_stop). >> >>> >> >>> Sorry for chiming in so late - I'm also on gentoo (kernel 6.5.5- >> >>> gentoo), but as a client of Windows AD. >> >>> >> >>> Just want to emphasize that using uninterruptible sleep has not just >> >>> unhappy but devastating side-effects. >> >>> >> >>> I have 8 processors and 16 cifsd-cfid-laundromat processes, so >> >>> /proc/loadavg reports a load average of 16 on a totally idle system. >> >>> >> >>> This means that load-balancing software will never start additional >> >>> tasks on this system - "make -l" but also any other load-dependent >> >>> system. Just reducing the number of cifsd-cfid-laundromat processes >> >>> does not fix this - even a single one makes loadavg report a wrong >> >>> result for load balancing. >> >>> >> >>> So, if cifsd-cfid-laundromat must really be uninterruptible, the only >> >>> solution would be to change the way loadavg is computed by the kernel >> >>> to exclude uninterruptible but sleeping processes. But must it be >> >>> uninterruptible? >> >>> >> >>> Thanks and best regards, >> >>> Bernd >> >> >> >>This is a huge problem here as well, as a client to Samba using SMB1 >> (for Unix extensions). >> >> >> >>For others encountering this problem, I was able to work around it with >> the following snippet: >> >> >> >>diff --git a/fs/smb/client/cached_dir.c b/fs/smb/client/cached_dir.c >> >>index 2d5e9a9d5b8b..fc2caccb597a 100644 >> >>--- a/fs/smb/client/cached_dir.c >> >>+++ b/fs/smb/client/cached_dir.c >> >>@@ -576,7 +576,7 @@ cifs_cfids_laundromat_thread(void *p) >> >> struct list_head entry; >> >> >> >> while (!kthread_should_stop()) { >> >>- ssleep(1); >> >>+ msleep_interruptible(1000); >> >> INIT_LIST_HEAD(&entry); >> >> if (kthread_should_stop()) >> >> return 0; >>
Do you have backports of these to 6.5? I tried to do it manually but there's already so many changes between 6.5 and these commits.
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